The White House said Iran needed to take "concrete steps" to ‘assure’ the United States and the international community that it was not pursuing nuclear weapons

The White House on Monday said Iran needed to take "concrete steps" to ‘assure’ the United States and the international community that it was not pursuing nuclear weapons.
  
"We're looking forward to these talks creating a conducive environment for concrete progress," Jay Carney, spokesman for President Barack Obama, told reporters ahead of key meetings this week between Tehran and world powers.
  
"We are very clear-eyed about what Iran needs to do in order to fulfill its international obligations and be able to reassure the international community that it is not pursuing nuclear weapons."We need concrete steps taken by the Iranians to assure that they will forsake their nuclear weapons ambitions," said Carney, as he welcomed talks set to take place in Istanbul later this week.
  
President Obama, added Carney, has already "made clear that the window is closing on Iran, that they need to treat these talks seriously because there is great concern around the world about Iran's pursuit of nuclear weapons."